No. 102 

1960 

VIRGINIA PINE SEED VIABLE 

TWO MONTHS BEFORE NATURAL CONE OPENING 

Virginia pine (Pinus virginiana Mill.) seed used in 

nurseries and for forest seeding ordinarily is collected 

from standing or felled trees in autumn. Some questions 

that concern the seed collector are: How early in the season 

does Virginia pine seed ripen? How does seed viability 

change if the cones are left on the felled trees? 

To help answer these questions, studies were made at 

the U. S. Forest Service's Laurel Research Center in central 

Maryland, where investigations are being conducted in Virginia pine management and silviculture. 

Methods 

In 1953 a preliminary study was made. Some 300 cones 

were collected from about 30 trees freshly felled during 

each of the following four periods: September 1-15; September 16-30; October 1-15; and October 16-31. The cones 

were dried until they opened. Two hundred seeds from each 

collection were then placed immediately to germinate in a 

well-watered mixture of sand and vermiculite. After 15 weeks 

@ the percentage of germination was recorded. 

In 1954 a more detailed study was begun. For this 

study 5 trees were felled each week during the 13-week period from August 2 until October 25. Cones were collected from 

the trees on the day they were felled; in addition, collections were made from the same trees 1, 2, 3, and 4 weeks 

after felling. Thus, cones from each group of 5 trees were 

collected on 5 dates. During each collection 10 cones were 

taken from each of the 5 trees and the 50 cones were immediately dried in circulating air at 75' F. After drying for 2 

days, they were placed in a large oven where air was circulated at a uniform temperature of 120° F. When most of the 
50 cones had opened, the seeds were extracted and cleaned. 

Viability was tested at once by placing a 100-seed sample in 

a well-watered mixture of sand and vermiculite at room temperature. 

Results and Discussion 

The pattern of seasonal seed viability uncovered by 

these studies was unexpected. It was found that Virginia 

pine cones could be collected as much as 9 weeks before 

normal opening in late October with assurance of moderate to 

good seed viability. This was noted in both 1953 and 1954. 

In both years the seed first became viable during August and 

reached high viability by the beginning of September. 

In 1953, this early September high was followed by a 

slight drop, and then in October a rise to maximum viability 

for the year: 

Collection Germination 

period (percent) 

September 1-15 45 

September 16-30 34 

October 1-15 54 

October 16-30 76 

Figure 1.--Collecting Virginia pine cones from a felled 

tree after an early September logging. 
Table 1.--Viability of Virginia pine seed. 

by date of collection. 1954 

In the more detailed study of seed ripening in 1954, 

Trees felled 

(date) Germinat ion 

Percent 

August 2 0 

August 9 1 

August 16 0 

August 23 25 

August 30 62 

September 7 86 

September 13 51 

maximum viability for the year--86 percent--was reached in 

early September; from then until natural seedfall in late 

October, germination tended to decline (table 1). This decline in germination is difficult to interpret. It has no 

known precedent in pine (r, 2, 3, 4), and is contradicted by 

the 1953 experiment. It is hoped that this aspect can be 

examined further, and conclusions can be made as to whether 

the decline in germination late in the fall of 1954 was due 

to faulty technique or was real. Whichever the case, in 

both 1953 and 1954 the seed did become viable enough in 

early September to justify collecting. 

In a second facet of the 1954 study, it was found 

that seed collected from trees that had been felled for 1 to 

4 weeks was as viable as seed collected the day of felling. 

1 

In fact, in certain cases, seed increased in viability by 

being left on the felled trees. This occurred on trees 

felled during the first two weeks in August. Apparently 

Trees felled 

(date) 

- 

some natural seed ripening continued. 

Germination 

Literature Cited 

Percent 

September 20 43 

September 27 43 

October 4 52 

October 11 36 

October 18 39 

October 25 37 

. 

(1) Fowells, Harry A. 

1949. An index of ripeness for sugar pine seed. 

U. S. Forest Serv. Calif. Forest and Range 

Expt. Sta. Forest Res. Note 64. 5 pp. 

(2) McLemore, B. F. 

1959. Cone maturity affects germination of longleaf 

pine seed. Jour. Forestry 57: 648-650. 
(3) Maki, T. E. 

1940. Significance and applicability of seed maturity indices for ponderosa pine. Jour. Forestry 38: 55-60. 

(4) Wakeley, Philip C. 

1954. Planting the southern pines. 

U. S. Dept. Agr., Agr. Monog. 18. 233 pp. 

--THOMAS W. CHURCH JR. 

and EDWARD I. SUCOFF 

Mr. Church, who formerly served as a research forester with the Northeastern Forest Experiment Station, is now 

at the Marquette Research Center of the Lake States Forest 

Experiment Station, Marquette, Michigan. Mr. Sucoff, a research forester, is with the Northeastern Station's Laurel 

Research Center, Laurel, Maryland.